Background
There is a growing public concern that exposure to radiofrequency electromagnetic fields (RF-EMFs) promotes cancer. Although the majority of studies have not found a significant association with increased cancer incidence and increase use of cell phones, some studies have indicated that there could be an increased risk of non-Hodgkin lymphoma, multiple myeloma and acute myeloid leukemia. This study used a mouse model for lymphoma to investigate whether disease progression changes as a result of RF-EMF exposure.

Objective
The objective of this study was to determine whether lymphoma disease progression is altered as a result of chronic exposure to combined RF-EMF in mice; the two frequencies used were code division multiple access (CDMA) and wideband code division multiple access (WCDMA).

Methods
The mice used in this study spontaneously develop T-lymphoid tumours within one year after birth. Four different groups of mice were used in the study: Group 1) male mice sham-exposed, Group 2) male mice RF-exposed, Group 3) female mice sham-exposed, and Group 4) female mice RF-exposed. RF-exposed mice were exposed for 45 minutes/day, 5 days a week for 42 weeks. Sham-exposed mice underwent the same conditions as RF-exposed mice but were not exposed to any RF- radiation. RF-exposure consisted of a combination of CDMA and WCDMA.
All mice were weighed regularly and blood samples taken once a month. Survival, lymphoma incidence and metastasis (organ involvement) were monitored and compared for all four groups.

Results
The researchers found that there was no significant difference in disease survival or progression between the exposed and sham-exposed groups. The only result that was significantly different was that the female mice exposed to RF radiation had a higher metastasis to the brain than sham-exposed animals.

Interpretation and Limitations
This study indicates that chronic combined exposure of CDMA and WCDMA RF-radiation does not enhance cancer progression or reduce survival time of a cancer patient. The amount of radiation the mice absorbed in these experiments were quite high compared to the restrictions recommended by the International Commission of Non-Ionizing Radiation Protection. Further research is needed to determine if the higher metastasis rate to brain in exposed female mice is a real event.

Conclusions
This study did not demonstrate that long term exposure to RF-radiation changed disease survival or progression in the lymphoma mouse model.